<!doctype html>
<!--
Copyright 2016 The Chromium Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
    <meta name="mobile-web-app-capable" content="yes">
    <meta name="apple-mobile-web-app-capable" content="yes">

    <!-- Origin Trial Token, feature = WebVR (For Chrome M59+), origin = https://webvr.info, expires = 2017-10-13 -->
    <meta http-equiv="origin-trial" data-feature="WebVR (For Chrome M59+)" data-expires="2017-10-13" content="Aqw0TUvp8CwZmgIS50pM1blhzy05y7OkBeW3AQQGjer4KuKV0p13xfrRbe2bT8B1+DgRW0O3Dda0yOjcL46GBwgAAABMeyJvcmlnaW4iOiJodHRwczovL3dlYnZyLmluZm86NDQzIiwiZmVhdHVyZSI6IldlYlZSMS4xIiwiZXhwaXJ5IjoxNTA3ODU5MDE4fQ==">

    <title>TEST - VR Links</title>

    <!--
      This test provides a couple of interactive VR elements that link to other
      pages, both 2D and WebVR-enabled, so that user agents can test their
      navigation behavior.
    -->

    <style>
      #webgl-canvas, #presenting-message {
        box-sizing: border-box;
        height: 100%;
        left: 0;
        margin: 0;
        position: absolute;
        top: 0;
        width: 100%;
      }
      #presenting-message {
        color: white;
        font-family: sans-serif;
        font-size: 2em;
        font-weight: bold;
        z-index: 1;
        text-align: center;
        padding: 0.5em;
        background-color: #444;
        display: none;
      }
    </style>

    <!-- This entire block in only to facilitate dynamically enabling and
    disabling the WebVR polyfill, and is not necessary for most WebVR apps.
    If you want to use the polyfill in your app, just include the js file and
    everything will work the way you want it to by default. -->
    <script>
      var WebVRConfig = {
        // Prevents the polyfill from initializing automatically.
        DEFER_INITIALIZATION: true,
        // Ensures the polyfill is always active when initialized, even if the
        // native API is available. This is probably NOT what most pages want.
        ALWAYS_APPEND_POLYFILL_DISPLAY: true,
        // Polyfill optimizations
        DIRTY_SUBMIT_FRAME_BINDINGS: true,
        BUFFER_SCALE: 0.75,
      };
    </script>
    <script src="js/third-party/webvr-polyfill.js"></script>
    <script src="js/third-party/wglu/wglu-url.js"></script>
    <script>
      // Dynamically turn the polyfill on if requested by the query args.
      if (WGLUUrl.getBool('polyfill', false)) {
        InitializeWebVRPolyfill();
      } else {
        // Shim for migration from older version of WebVR. Shouldn't be necessary for very long.
        InitializeSpecShim();
      }
    </script>
    <!-- End sample polyfill enabling logic -->

    <script src="js/third-party/gl-matrix-min.js"></script>

    <script src="js/third-party/wglu/wglu-debug-geometry.js"></script>
    <script src="js/third-party/wglu/wglu-program.js"></script>
    <script src="js/third-party/wglu/wglu-stats.js"></script>
    <script src="js/third-party/wglu/wglu-texture.js"></script>

    <script src="js/vr-cube-island.js"></script>
    <script src="js/vr-samples-util.js"></script>
  </head>
  <body>
    <canvas id="webgl-canvas"></canvas>
    <div id="presenting-message">Put on your headset now</div>
    <script>
      /* global mat4, VRCubeSea, WGLUStats, WGLUTextureLoader, VRSamplesUtil */
      (function () {
      "use strict";

      var PLAYER_HEIGHT = 1.65;

      var vrDisplay = null;
      var frameData = null;
      var projectionMat = mat4.create();
      var viewMat = mat4.create();

      var vrPresentButton = null;
      var presentingMessage = document.getElementById("presenting-message");

      var nextPageId;
      
      // ===================================================
      // WebGL scene setup. This code is not WebVR specific.
      // ===================================================

      // WebGL setup.
      var gl = null;
      var cubeIsland = null;
      var debugGeom = null;
      var stats = null;
      
      function onContextLost( event ) {
        event.preventDefault();
        console.log( 'WebGL Context Lost.' );
        gl = null;
        cubeIsland = null;
        debugGeom = null;
        stats = null;
      }

      function onContextRestored( event ) {
        console.log( 'WebGL Context Restored.' );
        initWebGL();
      }
      
      var webglCanvas = document.getElementById("webgl-canvas");
      webglCanvas.addEventListener( 'webglcontextlost', onContextLost, false );
      webglCanvas.addEventListener( 'webglcontextrestored', onContextRestored, false );

      function initWebGL() {
        var glAttribs = {
          alpha: false,
        };
        var pageId = WGLUUrl.getInt('id', 0);
        nextPageId = pageId + 1;
        var useWebgl2 = WGLUUrl.getBool('webgl2', false);
        var contextTypes = useWebgl2 ? ["webgl2"] : ["webgl", "experimental-webgl"];
        for (var i in contextTypes) {
          gl = webglCanvas.getContext(contextTypes[i], glAttribs);
          if (gl)
            break;
        }
        if (!gl) {
          var webglType = (useWebgl2 ? "WebGL 2" : "WebGL")
          VRSamplesUtil.addError("Your browser does not support " + webglType + ".");
          return;
        }
        gl.clearColor(0.1, 0.2, 0.3, 1.0);
        gl.enable(gl.DEPTH_TEST);
        gl.enable(gl.CULL_FACE);
        
        var textureLoader = new WGLUTextureLoader(gl);
        var texture = textureLoader.loadTexture("media/textures/cube-sea.png");
        cubeIsland = new VRCubeIsland(gl, texture, 2, 2);
        debugGeom = new WGLUDebugGeometry(gl);
        
        var enablePerformanceMonitoring = WGLUUrl.getBool(
            'enablePerformanceMonitoring', false);
        stats = new WGLUStats(gl, enablePerformanceMonitoring);

        window.addEventListener("resize", onResize, false);
        onResize();
        window.requestAnimationFrame(onAnimationFrame);
      }
      initWebGL();

      // ================================
      // WebVR-specific code begins here.
      // ================================

      function onVRRequestPresent () {
        // This can only be called in response to a user gesture.
        vrDisplay.requestPresent([{ source: webglCanvas }]).then(function () {
          // Nothing to do because we're handling things in onVRPresentChange.
        }, function (err) {
          var errMsg = "requestPresent failed.";
          if (err && err.message) {
            errMsg += "<br/>" + err.message
          }
          VRSamplesUtil.addError(errMsg, 2000);
        });
      }

      function onVRExitPresent () {
        if (!vrDisplay.isPresenting)
          return;

        vrDisplay.exitPresent().then(function () {
          // Nothing to do because we're handling things in onVRPresentChange.
        }, function (err) {
          var errMsg = "exitPresent failed.";
          if (err && err.message) {
            errMsg += "<br/>" + err.message
          }
          VRSamplesUtil.addError(errMsg, 2000);
        });
      }

      function onVRPresentChange () {
        onResize();

        if (vrDisplay.isPresenting) {
          if (vrDisplay.capabilities.hasExternalDisplay) {
            presentingMessage.style.display = "block";

            VRSamplesUtil.removeButton(vrPresentButton);
            vrPresentButton = VRSamplesUtil.addButton("Exit VR", "E", "media/icons/cardboard64.png", onVRExitPresent);
          }
        } else {
          if (vrDisplay.capabilities.hasExternalDisplay) {
            presentingMessage.style.display = "";

            VRSamplesUtil.removeButton(vrPresentButton);
            vrPresentButton = VRSamplesUtil.addButton("Enter VR", "E", "media/icons/cardboard64.png", onVRRequestPresent);
          }
        }
      }

      if (navigator.getVRDisplays) {
        frameData = new VRFrameData();

        navigator.getVRDisplays().then(function (displays) {
          if (displays.length > 0) {
            vrDisplay = displays[displays.length - 1];

            vrDisplay.depthNear = 0.1;
            vrDisplay.depthFar = 1024.0;

            if (vrDisplay.stageParameters &&
                vrDisplay.stageParameters.sizeX > 0 &&
                vrDisplay.stageParameters.sizeZ > 0) {
              cubeIsland.resize(vrDisplay.stageParameters.sizeX, vrDisplay.stageParameters.sizeZ);
            }

            if (vrDisplay.capabilities.canPresent)
              vrPresentButton = VRSamplesUtil.addButton("Enter VR", "E", "media/icons/cardboard64.png", onVRRequestPresent);

            // For the benefit of automated testing. Safe to ignore.
            if (vrDisplay.capabilities.canPresent && WGLUUrl.getBool('canvasClickPresents', false))
              webglCanvas.addEventListener("click", onVRRequestPresent, false);

            window.addEventListener('vrdisplaypresentchange', onVRPresentChange, false);
            window.addEventListener('vrdisplayactivate', onVRRequestPresent, false);
            window.addEventListener('vrdisplaydeactivate', onVRExitPresent, false);
          } else {
            VRSamplesUtil.addInfo("WebVR supported, but no VRDisplays found.", 3000);
          }
        }, function () {
          VRSamplesUtil.addError("Your browser does not support WebVR. See <a href='http://webvr.info'>webvr.info</a> for assistance.");
        });
      } else if (navigator.getVRDevices) {
        VRSamplesUtil.addError("Your browser supports WebVR but not the latest version. See <a href='http://webvr.info'>webvr.info</a> for more info.");
      } else {
        VRSamplesUtil.addError("Your browser does not support WebVR. See <a href='http://webvr.info'>webvr.info</a> for assistance.");
      }

      function onResize () {
        if (vrDisplay && vrDisplay.isPresenting) {
          var leftEye = vrDisplay.getEyeParameters("left");
          var rightEye = vrDisplay.getEyeParameters("right");

          webglCanvas.width = Math.max(leftEye.renderWidth, rightEye.renderWidth) * 2;
          webglCanvas.height = Math.max(leftEye.renderHeight, rightEye.renderHeight);
        } else {
          webglCanvas.width = webglCanvas.offsetWidth * window.devicePixelRatio;
          webglCanvas.height = webglCanvas.offsetHeight * window.devicePixelRatio;
        }
      }

      var leftIntersect = false;
      var rightIntersect = false;

      var playerPosition = [0, PLAYER_HEIGHT, 0];
      var leftPosition = [-0.5, PLAYER_HEIGHT, -1.0];
      var rightPosition = [0.5, PLAYER_HEIGHT, -1.0];

      function onClick () {
        if (leftIntersect) {
          // Navigate back to this page (with a different query string to force
          // navigation)
          window.location = "test-vr-links.html?id=" + nextPageId;
        } else if (rightIntersect) {
          // Navigate to a 2D site
          window.location = "index.html"
        } else {
          if (gl) {
            // Reset the background color to a random value
            gl.clearColor(
                Math.random() * 0.5,
                Math.random() * 0.5,
                Math.random() * 0.5, 1.0);
          }
        }
      }
      
      // Register for mouse restricted events while in VR
      // (e.g. mouse no longer available on desktop 2D view)
      function onDisplayPointerRestricted() {
        if (webglCanvas && webglCanvas.requestPointerLock) {
          webglCanvas.requestPointerLock();
        }
      }

      // Register for mouse unrestricted events while in VR
      // (e.g. mouse once again available on desktop 2D view)
      function onDisplayPointerUnrestricted() {
        var lock = document.pointerLockElement;
        if (lock && lock === webglCanvas && document.exitPointerLock) {
          document.exitPointerLock();
        }
      }
      
      webglCanvas.addEventListener("click", onClick, false);
      window.addEventListener('vrdisplaypointerrestricted', onDisplayPointerRestricted);
      window.addEventListener('vrdisplaypointerunrestricted', onDisplayPointerUnrestricted);

      function getStandingViewMatrix (out, view) {
        if (vrDisplay.stageParameters) {
          // If the headset provides stageParameters use the
          // sittingToStandingTransform to transform the view matrix into a
          // space where the floor in the center of the users play space is the
          // origin.
          mat4.invert(out, vrDisplay.stageParameters.sittingToStandingTransform);
          mat4.multiply(out, view, out);
        } else {
          // Otherwise you'll want to translate the view to compensate for the
          // scene floor being at Y=0. Ideally this should match the user's
          // height (you may want to make it configurable). For this demo we'll
          // just assume all human beings are 1.65 meters (~5.4ft) tall.
          mat4.identity(out);
          mat4.translate(out, out, [0, PLAYER_HEIGHT, 0]);
          mat4.invert(out, out);
          mat4.multiply(out, view, out);
        }
      }

      function renderSceneView (projection, view) {
        cubeIsland.render(projection, view, stats);

        debugGeom.bind(projection, view);

        if (leftIntersect) {
          debugGeom.drawCube(0, leftPosition, 0.35, [0.5, 0, 1, 1]);
        } else {
          debugGeom.drawCube(0, leftPosition, 0.3, [0, 0, 1, 1]);
        }

        if (rightIntersect) {
          debugGeom.drawCube(0, rightPosition, 0.35, [0.5, 1, 0, 1]);
        } else {
          debugGeom.drawCube(0, rightPosition, 0.3, [0, 1, 0, 1]);
        }
      }

      function lookingAtSphere(position, radius, pose) {
        var lookVec = vec3.fromValues(0, 0, -1);
        vec3.transformQuat(lookVec, lookVec, pose.orientation);

        var m = vec3.create();
        vec3.sub(m, playerPosition, position); 
        var b = vec3.dot(m, lookVec); 
        var c = vec3.dot(m, m) - radius * radius; 

        // Exit if player's origin outside of sphere (c > 0) and lookVec is pointing away from sphere (b > 0) 
        if (c > 0.0 && b > 0.0) 
          return false; 
        var discr = b*b - c; 

        // negative discriminant = lookVec misses sphere 
        return (discr >= 0.0);
      }

      function onAnimationFrame (t) {
        // do not attempt to render if there is no available WebGL context
        if (!gl || !stats || !cubeIsland || !debugGeom) {
          window.requestAnimationFrame(onAnimationFrame);
          return;
        }
        stats.begin();

        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

        if (vrDisplay) {
          vrDisplay.requestAnimationFrame(onAnimationFrame);

          vrDisplay.getFrameData(frameData);

          leftIntersect = lookingAtSphere(leftPosition, 0.35, frameData.pose);
          rightIntersect = lookingAtSphere(rightPosition, 0.35, frameData.pose);

          if (vrDisplay.isPresenting) {
            gl.viewport(0, 0, webglCanvas.width * 0.5, webglCanvas.height);
            getStandingViewMatrix(viewMat, frameData.leftViewMatrix);
            renderSceneView(frameData.leftProjectionMatrix, viewMat);

            gl.viewport(webglCanvas.width * 0.5, 0, webglCanvas.width * 0.5, webglCanvas.height);
            getStandingViewMatrix(viewMat, frameData.rightViewMatrix);
            renderSceneView(frameData.rightProjectionMatrix, viewMat);

            vrDisplay.submitFrame();
          } else {
            gl.viewport(0, 0, webglCanvas.width, webglCanvas.height);
            mat4.perspective(projectionMat, Math.PI*0.4, webglCanvas.width / webglCanvas.height, 0.1, 1024.0);
            getStandingViewMatrix(viewMat, frameData.leftViewMatrix);
            renderSceneView(projectionMat, viewMat);
            stats.renderOrtho();
          }
        } else {
          window.requestAnimationFrame(onAnimationFrame);

          // No VRDisplay found.
          gl.viewport(0, 0, webglCanvas.width, webglCanvas.height);
          mat4.perspective(projectionMat, Math.PI*0.4, webglCanvas.width / webglCanvas.height, 0.1, 1024.0);
          mat4.identity(viewMat);
          mat4.translate(viewMat, viewMat, [0, -PLAYER_HEIGHT, 0]);
          renderSceneView(projectionMat, viewMat);

          stats.renderOrtho();
        }

        stats.end();
      }
      })();
    </script>
  </body>
</html>
